Determination of Calcium in Iron-based Powder Metallurgy by Inductively Coupled Plasma Atomic Emission Spectrometry

A determination method of calcium in iron-based powder metallurgy has been established using inductively coupled plasma atomic emission spectrometry(ICP-OES). The acidity ratio and the interference of various factors were optimized. The external standard method was used to quantify and draw the calibration curve to eliminate the influence of the matrix effect, and the interference correction test of the coexisting elements showed that the coexisting elements in the sample has no interference effect on the element to be measured. A pretreatment of the sample was required by the sequential dissolution in aqua regia, heating on an electric heating plate, and followed by the further addition of H₂O₂. Good linearity was then obtained in the range of 0.5~10 mg/L with a correlation coefficiency of 0.999 9, a relative standard deviation of the instrument precision of 0.14% (n=10), and the recovery rate of standard addition in the range of 98%~105%. The method is economical, simple, rapid and reproducible, and can meet the requirements of the analysis and detection.